One of the complications related to studying Alzheimer's disease is the actual diagnosis. Unlike malignancies where a biopsy can be obtained, Alzheimer's disease is a diagnosis of exclusion or made at autopsy. While the Europeans have recently identified and agreed on CSF biomarkers for diagnosis of Alzheimer's disease, the investigators have not accepted that premise in the United States. At the present time, PET imaging which utilizes various compounds has been utilized to identify depositions of amyloid in the CNS. More recently, there is some suggestive evidence that a specific type of cataract may be seen in a high percentage of patients with Alzheimer's disease related to possible β Amyloid deposition in the lens region (29-30). Many rely on the NINCDS-ADRDA criteria for clinical diagnosis of Alzheimer's disease.